Helix nebula (NGC7293), narrowband OIII, logarithmic histogram scale


A logarithmic histogram stretch and a multicolored pallette has been applied to show a very faint outer structure (arrowed). I'm not convinced that this structure is real as it is very weak. Other inhomogenities are visible in the background, especially in the corners and the right half of the image. These are certainly artifacts from a process I applied correct for slight errors in my flatfields. The amplitude of these inhomogenities is just ~1/2 ADU, roughly 400 times less than the peak OIII nebula flux.

Here's my main page where you can see more of the pictures I have taken so far.


Comments greatly appreciated! (svlgrd@com.dtu.dk)